Capsule for beverage preparation with integrally formed sealing member

ABSTRACT

The invention relates to a capsule (10) designed for preparing a beverage upon injection of liquid into the capsule by means of a beverage preparation machine, the capsule (10) having a longitudinal axis (A) and comprising a cup-shaped base body (1) for holding beverage preparation ingredients, a flange-like rim (2) and sealing means (3) wherein the base body (1), the flange-like rim (2) and the sealing means (3) are made integrally from metallic material such as aluminum, as a one piece element, wherein the sealing means (3) comprises a dedicated surface (4) located on the base body (1) at the junction with the flange-like rim (2) and a projection (5) comprising at least one series of arc-shaped protrusions (5a) protruding circumferentially on the flange-like rim (2), characterized in that the dedicated surface (4) and the arc-shaped protrusions (5a) of the sealing means (3) are concentrically arranged such as to form an annular space (6) there-between for receiving at least one sealing surface (21a) of a capsule engagement member (21) of the beverage preparation machine (20).

FIELD OF THE INVENTION

The present invention relates to a capsule designed for preparation of a food product such as a beverage with enhanced sealing means. In particular, the invention relates to a capsule having a body with an integrally formed sealing member made from metallic material such as aluminum.

BACKGROUND AND OBJECT OF THE INVENTION

Capsules for preparation of a food product such as a beverage are widely known in the market. An example of such capsule that is intended for being used with a beverage preparation machine is described in EP 0 512 468 A1. For beverage preparation in a dedicated beverage preparation machine, the capsule (provided with a membrane) is inserted to the machine and ingredients contained in the capsule are made to interact with liquid provided to the capsule in order to form a desired beverage that is then made to leave the capsule. Thereby, the capsule is opened under the effect of rising pressure within the capsule, which urges an outlet face of the membrane against opening means such as raised elements provided on a supporting part of the beverage preparation machine. Sealing of the capsule during the beverage preparation process is obtained by an outer portion of a flange-like rim of the capsule that is contacted along a circumferential contact line by a suitably shaped engagement member of the beverage preparation machine.

In order to enhance sealing between the capsule and an engagement member of the beverage preparation machine, capsules have been developed in which a dedicated sealing member is applied and wherein the sealing member is of different material than the capsule body. EP 1 654 966 A1, EP 1 849 715 A1 and EP 2 151 313 A1, for example, relate to such a capsule in which a sealing member of rubber elastic material is applied to the capsule. The sealing member may be applied onto the capsule body by means of liquid depositing and hardening, gluing or by crimping a portion of the capsule body and/or the flange-like rim of the capsule onto the sealing member.

A disadvantage of these capsules is a more complex manufacturing process in which the capsule and the sealing member are manufactured in individual manufacturing steps and then assembled. The solution is also costly to produce both in terms of material cost and production cost and it has also an environmental impact due to the use of two different materials. Therefore, a solution is sought-after which enables a facilitated manufacturing process while at the same time providing enhanced sealing properties of the flange-like rim of the capsule.

Capsules are also known, which comprise an integrally formed sealing member, i.e. a sealing member made from the same material as the capsule body respectively the flange-like rim of the capsule. EP 1 654 966 A1, EP 2 303 077 B1, EP 2 387 922 B1 and EP 2 814 328 B1, for example, relate to a capsule comprising a sealing member formed of a plurality of concentric annular projection in the form of protrusions or steps integrally formed with the flange-like rim.

EP 1 654 966 A1 discloses, in its third embodiment, to have the resilient nature of the sealing member made by the geometrical shape of the capsule itself. It proposes to have the sealing member in the shape of a step that increase the diameter of the side wall of the capsule . When the capsule is engaged with the inclined sealing surface of the beverage preparation machine, a deflection of the sealing member occurs on the capsule.

WO2014/012783 A1, WO2014/184652 A1, WO2016/186489 A1, WO2016/186495 A1 and WO2016/186496 A1 also disclose capsules for beverage preparation and which comprise a flange-like rim portion with an integrally formed annular sealing member.

WO2016/186495 A1 relates to a plastic capsule comprising a flange-like rim with two spaced projections projecting axially from the flange-like rim and a plateau between the two projections. During extraction of the capsules, a specific part of the beverage preparation machine is configured to interact with the projections and the plateau to provide sealing engagement.

WO2016/207845 A1 relates to a plastic capsule comprising a flange-like rim with a single annular sealing ring that is enclosed by inner and outer centering projections. The centering projections comprise a multitude of arc-shaped elements separated circumferentially by gaps which are designed to provide a better centering of the sealing ring with respect to a circumferential sealing edge of a beverage preparation machine.

These known capsules however suffer the disadvantage that due the manufacturing tolerances in the dimensions of the capsules and in those of the enclosing member of the beverage preparation machine, the two parts are not properly matching and engaging, thus reducing the tightness between capsule and engagement member with risk of leaks and beverage dilution with water.

Furthermore, due to the circumferentially arranged projections of the flange-like rim, tensions may occur during forming of the projections in the manufacturing process, which in turn lead to defects in the sealing member and/or the flange-like rim and which negatively affect the sealing properties of the sealing member.

This particularly applies for metal capsules, e.g. made from aluminum or aluminum alloy. Thereby, defects such as stress cracking, wrinkling and other surface defects may occur during the deep drawing process of aluminum when forming the capsule.

In addition, the circumferentially arranged sealing protrusions may lead to a less tolerant sealing adjustment with concentricity problems.

It is therefore an object of the present invention to provide an improved capsule which overcomes the disadvantages of the prior art solutions. This object is solved by the independent claims. The dependent claims define further preferred embodiments of the invention.

SUMMARY OF THE INVENTION

The invention relates to a capsule designed for preparing a beverage upon injection of liquid into the capsule by means of a beverage preparation machine, the capsule having a longitudinal axis and comprising a cup-shaped base body for holding beverage preparation ingredients, a flange-like rim and sealing means. Specifically, the base body, the flange-like rim and the sealing means are made integrally from metallic material such as aluminum, as a one piece element and the sealing means comprise a dedicated surface located on the base body at the junction with the flange-like rim and a projection comprising at least one series of arc-shaped protrusions protruding circumferentially on the flange-like rim.

According to the invention, the dedicated surface and the arc-shaped protrusions of the sealing means are concentrically arranged such as to form an annular space there-between for receiving at least one sealing surface of a capsule engagement member of the beverage preparation machine.

The capsule according to the invention enables a reliable and tolerant sealing structure made from a single integral piece and thus by omitting any additional material such as rubber. The capsule may thus be formed in a facilitated manufacturing process at reduced costs, while at the same time providing an enhanced sealing member without any material defects such as cracks, wrinkling and surface defects that could affect the capsule quality and tightness and as well the extraction process.

The arc-shaped protrusions of one series of protrusion and dedicated surface being arranged such that the protrusions are at least partially covering the dedicated surface in side view.

The flange-like rim is preferably an essentially planar collar that extends from an open end of the cup-shaped base body essentially perpendicular to outer lateral sidewalls of the base body and/or to a rotational axis of the capsule. The series of arc-shaped protrusions are arranged distant from the cup-shaped base body and from the outer periphery of the flange-like rim.

The arc-shaped protrusions and dedicated surface of the sealing member are preferably integrally formed in the otherwise essentially planar flange-like rim. The protrusions formed in the flange-like rim may comprise a material thickness essentially corresponding to the rest of the flange-like rim.

The arc-shaped protrusions and dedicated surface in the flange-like rim are preferably made by a deep-drawing process. In a preferred embodiment, the capsule body, the flange-like rim and the sealing member may be manufactured using deep-drawing process. The capsule may e.g. be produced by deep-drawing an initially flat metal sheet. The capsule is preferably made from a single sheet of metal such as aluminum.

In the proposed embodiments, the arc-shaped protrusions of one series of protrusions are arranged equidistant to the dedicated surface such as to form a circumferentially constant annular space between the dedicated surface and the arc-shaped protrusions.

Preferably, the annular space extends over a radial distance asD (corresponding to the distance between the dedicated surface and the arc shaped protrusions) comprised between 0.25 and 0.80 mm.

The dedicated surface and the arc-shaped protrusions of the sealing member are arranged on the same surface of the flange-like rim. The surface is directed towards the cup-shaped base body of the capsule. On a surface of the flange-like rim opposite thereto, a closing membrane may be connected to the capsule base body.

In the proposed solution, the dedicated surface extends over a radial distance D comprised between 0.1 and 0.6 mm to cooperate with the sealing surface of the capsule engagement member.

Hence, when the capsule is used in the beverage machine, the capsule engagement member interact, on one side with the dedicated surface and on the other side with the arc shaped protrusions.

Preferably, the dedicated surface is selected in the group of a step, an inclined surface, a double step or a combination thereof.

When the dedicated surface is in the form of a step, it has a height H comprised between 0.5 and 3 mm.

When the dedicated surface is an inclined surface, it is inclined vis à vis the external surface of the base body. The inclination may be of an angle that is a sharp angle or a reflex angle.

The arc-shaped protrusions of the series arc shaped protrusions of the sealing member are preferably continuous protrusions with gaps formed between the respective protrusions of a given series. The gaps are thus annular gaps that extend between respective adjacent arc-shaped protrusions of a given series.

The series of arc-shaped protrusions may each comprise a multitude of arc-shaped protrusions, preferably, at least two, at least three, four, five or six arc-shaped protrusions.

In one series of arc shaped protrusions, the protrusions extend over a total angle comprised between 200 and 340°, which allows a good angular overlap with the dedicated surface, and therefore participate in an efficient sealing with the engagement member.

Indeed, the angular overlap between the dedicated surface and the arc-shaped protrusions equals at least 60 to 95%, preferably 75 to 85%.

Preferably, the arc-shaped protrusions are arranged distant from the cup-shaped base body and from an outer periphery of the flange-like rim and the annular space between the dedicated surface and the arc-shaped protrusions is void of any protrusion for receiving the annular sealing surface of a capsule engagement member of the beverage preparation machine.

A bottom portion of the annular space is preferably a flat annular portion. The bottom portion of the annular space preferably corresponds to an upper surface of the flange-like rim portion.

The engagement member is preferably an essentially bell-shaped engagement member respectively a so-called capsule cage designed to house the cup-shaped base body of the capsule. The sealing surface of the engagement member may be a flat or rounded end surface of the engagement member.

In a preferred mode, the sealing surface of the engagement member is arranged for engaging the annular space between the dedicated surface and the series of arc shaped protrusions. The engagement of the sealing surface of the engagement member may be such that it may deform at least partially the protrusions and dedicated surface. The engagement of the sealing surface of the engagement member may be such that it provides at least substantially radially oriented sealing forces with the protrusions and dedicated surface.

The radial distance asD of the annular space is preferably chosen such as to be equal to or less than the radial length L of the sealing surface of the capsule engagement member in order to provide efficient fluid tightness.

In a preferred embodiment, the radial distance asD is chosen to be at least 1-2%, preferably at least 2-5% less than the radial length L of the annular sealing surface of the engagement member of the beverage preparation machine.

The arc-shaped protrusions of the sealing means are arranged at a radial distance d of between 0.5 to 1.2 mm, more preferably between 0.8 and 1.0 mm from the base body.

The arc-shaped protrusions of the series of arc shaped protrusions preferably comprise a base width BW of between 0.3 and 1.3 mm, preferably between 0.5 and 1.0 mm and/or a height h of between 0.8 and 1.7 mm, preferably between 1 and 1.5 mm.

The respective protrusions preferably comprise in sectional side view a lower base portion B with two opposing preferably linear wall sections and an upper portion A with two opposing preferably rounded wall sections.

The two opposing rounded wall sections of the upper portion A are preferably joined by a rounded tip portion C.

The two opposing linear wall sections are preferably arranged to converge towards the upper portion A of the respective protrusions. The two opposing linear wall sections are preferably arranged at an angle of inclination of between 3 to 12°, more preferably of between 5 to 10° with respect to the normal of the flange-like rim and/or with respect to a rotational axis of the capsule.

The two opposing rounded wall sections of the upper portion A preferably comprise a radius R1 of between 0.5 to 5.5, more preferably between 1 and 5 mm.

The rounded tip portion C preferably comprise a radius R2 of between 0.2 and 2.3 mm, more preferably between 0.5 and 2 mm.

The two opposing wall sections of the lower portion B may be not strictly linear but slightly convex. For example, the two opposing wall sections A and B may form together continuously convex wall sections of increasing curvature in direction to the tip portion C.

The capsule preferably further comprises a closing membrane connected to the base body and/or the flange-like rim of the capsule. The closing membrane is preferably connected to a surface of the flange-like rim opposite to the surface at which the inner and outer series of arc-shaped protrusions are arranged. The closing membrane may be connected to the flange-like rim by means of an adhesive and/or welding technique. The closing membrane is preferably a closed membrane, i.e. void of any perforations. The closing membrane may however as well comprise pre-formed perforations therein. The closing membrane is preferably an aluminum foil. The foil is preferably sealed to the flange-like rim such as to form a seal hermetical to gas with the capsule base body for preserving freshness of the ingredients contained in the cartridge.

The thickness of the closing membrane preferably lies between 50 and 100 microns (including the embossed structure and lacquer(s) on surface).

In a further aspect, the invention relates to a system comprising a capsule as described above and a beverage preparation machine designed to provide heated and/or pressurized liquid into the capsule for preparing a beverage upon interaction of the liquid with ingredients held within the capsule.

The beverage preparation machine preferably comprises a pump, heating and/or cooling means, a liquid supply such as a water tank and/or a beverage brewing chamber for selectively receiving a capsule in order to prepare a beverage therefrom.

The beverage preparation machine preferably comprises a capsule engagement member, e.g. as part of the brewing chamber, which is designed to house a capsule and in particular the capsule base body when the capsule is provided into the machine. The engagement member comprises an annular sealing surface designed to interact with the sealing member of the capsule in order to enable an effective sealing of the capsule during the beverage preparation process. As mentioned earlier, the sealing surface of the engagement member may be arranged for engaging the dedicated surface and the arc shaped protrusions of the series of arc-shaped protrusions.

The beverage preparation machine preferably further comprises perforation means such as injection blades or the like, which are designed to perforate an inlet face of the capsule, in particular situated at a closed end of the capsule base body, and to inject liquid into the capsule interior.

The beverage preparation machine preferably further comprises a capsule support designed to hold the flange-like rim of the capsule at a side opposite to a side at which the engagement member of the machine engages the sealing member of the capsule. The capsule support preferably comprises opening means such as e.g. truncated pyramid-like elements against which a closing membrane of the capsule may be urged during pressure rise within the capsule such as to open the closing member e.g. by of tearing or rupturing.

The capsule according to the present invention is preferably rotational symmetric, i.e. symmetric along its vertical axis.

The beverage preparation ingredients provided in the capsule are preferably chosen from the group consisting of roasted ground coffee, tea, instant coffee, a mixture of roasted ground coffee and instant coffee, a syrup concentrate, a fruit extract concentrate, a chocolate product, a milk-based product or any other dehydrated edible substance, such as dehydrated stock. The liquid to be used for beverage preparation is preferably water of any temperature.

The invention further relates to a cup-shaped base body of a capsule for preparation of a food product with an enhanced integrally formed sealing member comprising a dedicated surface and a circumferentially arranged projection for receiving there-between a sealing surface of a capsule engagement member of the beverage preparation machine.

BRIEF DESCRIPTION OF THE FIGURES

Further features, advantages and objects of the present invention will become apparent for a skilled person when reading the following detailed description of embodiments of the present invention, when taken in conjunction with the figures of the enclosed drawings.

These drawings depict only some embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. Hence, it will be appreciated that the invention as claimed is not intended to be limited in any way by these examples.

FIG. 1a is a perspective view of a preferred embodiment of a capsule according to the invention.

FIG. 1b is a top view of the capsule according to FIG. 1 a.

FIG. 2a is a schematic top view of a first embodiment of a capsule according to the invention.

FIG. 2b is a cross sectional side view of the capsule according to the invention in direction A-A of FIG. 1 b.

FIG. 3 is a cross sectional side view of a protrusion of the sealing member according to a first embodiment of the invention.

FIG. 4a is a sectional side view in direction D-D of FIG. 1b of a first embodiment of the sealing member according to the invention.

FIG. 4b is a sectional side view in direction E-E of FIG. 1b of a first embodiment of the sealing member according to the invention.

FIG. 5a is a sectional side view in direction D-D of FIG. 1b of a first embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine before engaging with each other.

FIG. 5b is a sectional side view in direction E-E of FIG. 1b of a first embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine before engaging with each other.

FIG. 6a is a sectional side view in direction D-D of FIG. 1b of a first embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine after engaging with each other.

FIG. 6b is a sectional side view in direction E-E of FIG. 1b of a first embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine after engaging with each other.

FIG. 7 is a sectional side view of second embodiment of the sealing member according to the invention.

FIG. 8 is a sectional side view of third embodiment of the sealing member according to the invention.

DETAILED DESCRIPTION OF THE FIGURES

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof.

In the drawings, similar symbols and references typically identify similar components, unless context dictates otherwise.

The illustrative embodiments described in the detailed description and drawings are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the claimed subject matter presented here.

It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean including, but not limited to.

Any reference to prior art documents in this specification is not to be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.

FIGS. 1a and 1b relate to a preferred embodiment of a capsule 10 according to the invention and respectively represents perspective side view and top view of said preferred embodiment. The capsule 10 comprises a cup-shaped base body 1. The base body 1 comprises a closed end 10 a, a sidewall 10 b forming the external surface of the base body 1 and an open end 10 c. The closed end 10 a may serve as an injection face during a beverage preparation process, which may be opened by a dedicated injection member of a beverage preparation machine 20 (not represented in FIGS. 1a and 1b ).

The capsule 10 further comprises a flange-like rim 2 which is preferably arranged at the open end 10 c of the capsule 10. The flange-like rim 2 may extend radially outwardly from lateral sidewalls 10 b of the cup-shaped base body 1. The flange-like rim 2 is preferably arranged transversally to a rotational axis Y of the capsule 10 (rotational axis Y also corresponds to the longitudinal axis A of the capsule 10).

The flange-like rim 2 presents at least one upper annular surface 2 a, said surface being directed towards the capsule base body 1 thus facing away from the open end 10 c of the capsule, at least one lower annular surface 2 b, which surface 2 b is directed away from the capsule base body 1 and a curled outer edge 2 c at its outer periphery (extremity of the flange-like rim 2 opposite the base body 1).

In the shown embodiment, the capsule is preferably made of aluminum.

At the open end 10 c of the capsule base body 1 a closing membrane 9 may be arranged. The closing membrane 9 is preferably connected to the flange-like rim 2. The closing membrane 9 is preferably connected to the lower annular surface 2 b of the flange-like rim 2.

Alternatively, the closing membrane 9 may be connected to the base body 1 or to both the base body 1 and the flange-like rim 2.

The closing membrane 9 is preferably an aluminum foil sealed to the flange-like rim 2.

The cup-shaped base body 1 preferably encloses beverage ingredients suitably for preparing a liquid comestible upon interaction with liquid injected into the capsule 10. The ingredients are preferably enclosed by the cup-shaped base body 1 and the closing membrane 9. The beverage ingredients may be roasted ground coffee or other kinds of ingredients as previously described.

For the preparation of a beverage, the capsule 10 is inserted into the dedicated beverage preparation 20 (presented in FIGS. 5a to 6b ). During the extraction process, an engagement member 21 (presented in FIGS. 5a to 6b ) of the beverage preparation machine 20 is engaged with the capsule 10: When the capsule 10 is placed into the beverage preparation machine 20, the engagement member 21 is lowered onto the capsule 10 by means of a dedicated closing force F.

The engagement member 21 comprises a sealing profile presenting at least one sealing surface 21 a (presented in FIGS. 5a to 6b ) coming into contact with the capsule 10.

A radial length L of the sealing surface 21 a is defined. The radial length L of the sealing is preferably between 0.5 to 2.0 mm.

Going in more detail, the flange-like rim 2 comprises an integrally formed sealing member 3 that is arranged at the upper annular surface 2 a of the flange-like rim.

The cup-shaped base body 1, the flange-like rim 2 and the sealing member 3 are integrally formed, i.e. as one single piece made from the same material. Accordingly, the cup-shaped base body 1, the flange-like rim 2 and the sealing member 3 can be manufactured from the same material by a forming process. In particular, the base body 1, the flange-like rim 2 and the integrally formed sealing member 3 can be formed in a deep-drawing process. The deep drawing process may require more than one deep drawing step to properly form from a flat piece of material the body of the capsule and the sealing member.

In the proposed embodiment, the base body 1, the flange-like rim 2 and the sealing means 3 are made integrally from metallic material such as aluminum, or aluminum alloy as a one piece element.

As shown in FIG. 1b , the sealing member 3 comprises a dedicated surface 4, located at the junction between the lateral sidewalls 10 b of the body base 1 and the flange-like rim 2, and a circular projection 5 comprising at least one series of arc-shaped protrusions 5 a protruding on the flange-like rim 2.

In the embodiment presented in the figures, the circular projection 5 comprises one series of arc-shaped protrusions 5 a, comprising individual arc-shaped protrusions 5 a arranged at a predefined radius about a rotational axis Y of the capsule 10.

The series of arc-shaped protrusions 5 a are concentrically arranged on the flange-like rim 2. The series of arc-shaped protrusion 5 a are integrally formed with the flange-like rim 2. This means that they are formed of same material as the flange-like rim and from the flange-like rim such as (and are not add-on parts) to protrude from the surface 2 a.

The series of arc-shaped protrusions 5 a is preferably arranged on the surface 2 a distant from the curled outer circumferential edge 2 c of the flange-like rim 2. The series of arc-shaped protrusions 5 a is further arranged distant from the dedicated surface 4 and from the cup-shaped base body 1 of the capsule 10.

The relative position of the series of arc-shaped protrusions 5 a on the flange-like rim 2 naturally depends on the matching position of the sealing surfaces of the sealing profile determined by the dimensions of the engaging member 21.

Other configuration of the series of arc-shaped protrusion and of the arc-shaped protrusions themselves may apply. p Indeed, the series arc-shaped protrusion 5 a may comprises at least two, preferably at least three, four, five or six arc-shaped protrusions 5 a.

The arc-shaped protrusions 5 a of the series of arc-shaped protrusion are preferably continuous protrusions with gaps 5 b formed there-between.

The dedicated surface 4 comprises a step 4 a extending from the lateral sidewalls 1 b over the flange-like rim 2, the step 4 a being substantially parallel to the flange-like rim direction. The step 4 a is integrally formed with the flange-like rim 2 and the base body 1 meaning it is formed from the flange-like rim such as (and are not add-on parts) to extend from the surface 2 a.

As can be seen in FIG. 1b , the step 4 a extends continuously and annularly around the lateral sidewalls 1 b and is arranged to cooperate with the sealing surface 21 a of the capsule engagement member 21. This is visible in FIGS. 5a to 6b (further described) showing the capsule 10 interacting with the engagement member 21 of the beverage machine 20.

The dedicated surface 4 in the forms of a step 4 a extends over a radial distance D.

The radial distance D is comprised in the range from 0.25 to 0.8 mm.

In the present embodiment, radial distance D is about 0.5 mm.

Additionally, step 4 a has a height H comprised between 0.5 and 3 mm.

The dedicated surface 4 (step 4 a) and the series of arc-shaped protrusions 5 a are arranged to form an annular space 6 there-between for receiving the sealing surface 21 a of the capsule engagement member 21.

In more detail, the series of arc-shaped protrusions 5 a of one series of protrusions are arranged equidistant to the dedicated surface 4 such as to form constant circumferentially annular space 6 between the dedicated surface 4 and the series of arc-shaped protrusions 5 a.

A radial distance asD is defined between the step 4 a and the arc-shaped protrusions 5 aand correspond to the extension of the annular space 6. The radial distance asD is preferably chosen such that the step 4 a of the dedicated surface 4 and the arc-shaped protrusions 5 a suitably interact in sealing engagement with the dedicated sealing surface 21 a of the engagement member 21.

More particularly and as will be further described, in the overlap region between the engagement member 21 and the capsule 10 (see FIGS. 5a to 6b ), the sealing surface 21 a actually splits into a sealing surface portion S1 which engages the step 4 a of the dedicated surface 4, a sealing surface portion S2 which engages the flange like rim 2 in the annual space 6, and a sealing surface portion S3 which engages the protrusions 5 a of the series of arc-shaped protrusions.

The radial distance asD is preferably between 0.25 to 0.8 mm, more preferably between 0.35 and 0.65 mm.

The annular space 6 between the step 4 a and arc-shaped protrusions 5 a is preferably void of any protrusion. The annular space 6 thus preferably comprises an essentially flat annular bottom surface 2 d (presented in FIG. 4b ) which interconnects the dedicated surface 4 and the arc-shaped protrusions 5 a.

As mentioned, the closing membrane 9 is connected to an annular outer portion of the surface 2 b of the flange-like rim. The closing membrane 9 may additionally be connected to intermediate annular surfaces 2 d arranged between the outer annular surface 2 b and the capsule base body 1.

Alternatively, the closing membrane 9 is preferably sealed on the annular bottom surfaces 2 d and onto the outer annular surface 2 b.

In the proposed embodiment, the annular bottom surface 2 d between the step 4 a and the arc shaped protrusions 5 a is preferably not elevated or lowered relative to the outer annular surface 2 b of the flange like rim 2. Preferably, the annular bottom surfaces 2 d and the outer annular surface 2 b are preferably substantially aligned.

The dedicated surface 4 and the series of arc-shaped protrusions 5 a are arranged such as to overlap in side view of the capsule with the sealing surface 21 a of the engagement member 21.

FIG. 2a relates to a schematic top view onto a capsule 10 according to the invention in which the respective radii of the capsule 10 are indicated. As shown in FIG. 2a , the capsule base body 1 and the flange-like rim 2 merge at a circumferential edge indicated as r1. Said radius r1 preferably lies between 12 and 18 mm, and most preferably is 15 mm. The outer radius r5 of the flange-like rim 2 at the curled outer edge 2 c preferably lies between 18 and 20 mm, and most preferably is 18.5 mm.

As shown in FIG. 2a , the series of arc-shaped protrusions 5 a of the series of arc shaped protrusions 5 a comprises circumferentially extending gaps 5 b formed between the respective arc-shaped protrusions 5 a of said series.

The series of arc-shaped protrusions 5 a extends over a total angle that is between 200 and 340° when seen in top view.

Hence, as the dedicated surface is circumferentially continuous over 360°, the overlap with the dedicated surface 4 (step 4 a) lies over an angle between 200 and 340°.

The respective arc-shaped protrusions 5 a of the series of arc-shaped protrusions 5 a are presently arranged circumferentially at equidistance to the dedicated surface 4 such as to form constant circumferentially extending arc-shaped protrusions 5 a separated by extending gaps 5 b between the arc shaped protrusions 5 a.

The difference between r1 and r2, presented in FIG. 2a , corresponds to the radial extension of the dedicated surface 4 and specifically of the step 4 a.

The difference between r2 and r3 corresponds to the radial extension of the annular space, thus to the distance of the annular space 6, asD.

The radial distance of the annular space 6, asD preferably lies between 0.25 and 0.8 mm.

The difference between r3 and r4 corresponds to a radial extension of the arc-shaped protrusions 5 a and the respective intermediate gaps 5 b of the series of arc shaped protrusions 5 a, thus to the distance of radial extension of the arc shaped protrusions 5 a, pD (represented in FIG. 4b ).

The radial extension of the arc-shaped protrusions 5 a, pD, preferably lies between 0.3 and 1.3 mm, more preferably between 0.5 and 1.0 mm.

FIG. 3 relates to a cross section side view of an exemplary embodiment of an arc-shaped protrusion 5 a.

The arc shaped protrusions 5 a preferably comprise a lower base portion B with two opposing linear wall sections b1 and b2 and an upper portion A with two opposing rounded wall sections a1 and a2. The two opposing rounded wall sections a1 and a2 of the upper portion A are preferably joined by a rounded tip portion C.

The two opposing linear wall sections b1,b2 are preferably arranged to approach towards the upper portion A of the arc shaped protrusions 5 a. The two opposing linear wall sections b1,b2 are preferably arranged at an angle a of inclination of between 3 to 12°, more preferably of between 5 to 10° with respect to the normal N of the flange-like rim 2 and/or with respect to a rotational axis Y of the capsule 10.

The two opposing rounded wall sections a1,a2 of the upper portion A preferably comprise a radius R1 of between 0.5 to 5.5 mm, more preferably between 1 and 5 mm. The rounded tip portion C preferably comprise a radius R2 of between 0.2 and 2.3 mm, more preferably between 0.5 and 2 mm.

A base width BW, corresponding to the maximum radial extension of the arc shaped protrusions 5 a, pD, preferably lies between 0.3 and 1.3 mm, more preferably between 0.5 and 1.0 mm. The height h preferably lies between 0.8 and 1.7 mm, more preferably between 1 and 1.5 mm.

The base portion B preferably extends to a height hl of between ⅓ to ½ of overall height h. Correspondingly, upper portion A may extend to a height h2 of between ⅔ to ½ of overall height h.

The arc shaped protrusions 5 a may comprise free ends 7 a, 7 b of progressively reducing dimensions to ensure a smoother transition with the surface 2 a of the flange-like rim. The width r4-r3 and height h at these free ends 7 a, 7 b preferably diminish progressively towards circumferentially extending gaps 5 b. In particular, the shape of these ends 7 a, 7 b may be slightly triangular or rounded when viewed from the top in direction of the flange-like rim as illustrated in FIG. 3. As a result, the forming of the projections is facilitated with lower risk of cracks or wrinkles.

FIG. 4a and FIG. 4b are sectional side view according to different directions, respectively D-D and E-E as presented in FIG. 1b , of a preferred embodiment of the sealing member 3 of the capsule 10.

As shown in FIG. 4b , the arc shaped protrusions 5 a of the sealing member 3 are preferably hollow. Accordingly, the arc shaped protrusions 5 a are not filled with material of the flange-like rim 2, but are formed by a contour of wall thickness t2. The arc shaped protrusions 5 a thus preferably form a hollow body that is open to the lower surface 2 b of the flange-like rim 2.

Due to the drawing process, the wall thickness t1 of the flange-like rim 2 may generally be slightly larger than the wall thickness t2 of the arc shaped protrusions 5 a for the same reason, the wall thickness t1, t2 may generally be larger than the wall thickness tb of the base body 1 of the capsule.

FIG. 5a and FIG. 5b are sectional side view according to different directions, respectively D-D and E-E as presented in FIG. 1b , of a preferred embodiment of the sealing member 3 of the capsule 10 and an engagement member 21 of a beverage preparation machine 20 before engaging with each other.

The system to which the capsule and the beverage preparation machine are integrated in, is operated as follows for the preparation of a cup of a beverage, for example, a coffee. The capsule 10 is placed in the beverage preparation machine and the capsule engaging member 21 is brought into contact with the capsule 10 when the beverage preparation machine is closed.

The engagement member 21 is preferably an essentially hollow bell-shaped engagement member for receiving the capsule base body 1 therein.

As mentioned, the engagement member comprises a sealing surface 21 a that may be an annular lower surface with rounded inner and outer circumferential edges. The front surface 21 a comprises a radial portion P presenting a thickness L that preferably lies between 0.8 and 1.2 mm, more preferably between 0.9 and 1.1 mm.

When the capsule 10 is placed into the beverage preparation machine 20, the engagement member 21 will be lowered onto the capsule 10 by means of a dedicated closing force F.

Starting from the position shown in FIG. 4a, 4b , when the engagement member 21 is lowered onto the sealing member 3 the annular sealing surface 21 a will first cooperate with the step 4 a (FIG. 5a /5 b) and then engage with the annular space 6 (FIG. 6a /6 b) thereby providing a fluid tight engagement between the sealing surface 21 a and the neighboring dedicated surface 4 (step 4 a) and the arc-shaped protrusions 5 a of the sealing member 3.

The capsule is pierced on its closed end 10 a by piercing means (not represented) for creating the entrance of a fluid (hot or cold) under pressure into the capsule 10. The water wets the coffee stored inside the capsule and extracts the desired substance to form the coffee beverage.

During the supply of the water under pressure to the capsule, the rise in pressure causes the closing membrane 9 to rupture (through pressing of the closing membrane 9 on some cover piercing means, for example) and the coffee beverage is delivered by drainage of the coffee beverage from the capsule to a cup.

In more details, as shown in FIGS. 5a and 5b , when the engagement member 21 is lowered down on the capsule, an edge of the radial portion P of the annular sealing surface 21 a first cooperates with the edge of step 4 a.

Reference is now made to FIG. 6a and FIG. 6b presenting sectional side view according to different directions, respectively D-D and E-E as presented in FIG. 1b , of a preferred embodiment of the sealing member 3 of the capsule 10 and an engagement member 21 of a beverage preparation machine 20 after engaging with each other.

As can be particularly seen in FIGS. 6a and 6b , the annular space 6 between the dedicated surface 4 (in the form of a step 4 a) and the arc shaped portions 5 a of the sealing member 3 is designed for receiving the sealing surface 21 a of the capsule engagement member 21 of the beverage preparation machine 20.

Thus, portion P of the sealing surface 21 a is received in the annular space 6 between the step 4 a and the arc shaped protrusions 4 a (section side view E-E) in which,

-   -   sealing surface portion S1 engages step 4 a on its vertical         portion, and     -   sealing surface portion S3 engages protrusions 5 a on one of its         faces.

In the proposed embodiment, in addition to sealing engagement of sealing surface portions S1 and S3, sealing surface portion S2 also engages the flange like rim 2 on bottom surface 2 d of the annual space 6, however the fact that this last engagement occurs may depend on the geometry of dedicated portion 4, art shaped protrusion 5 a and annular space 6.

Hence, the engagement of the sealing surface 21 is completed both by the engagement of the sealing surface portion S3 with the wall of the protrusions 5 a of the series of arc shaped protrusions and by the engagement of the sealing surface portion S1 with the vertical wall of step 4 a of the inner series.

In the present case, radial distance asD of annular space 6 is similar or less than the radial length L of the sealing portion P of sealing surface 21 a thereby allowing engagement of the sealing surface 21 in the annular space 6 for completion of sealing engagement. Indeed, as the sealing portion P is fully inserted in annular space 6, an efficient fluid tightness is operated.

Additionally, the rounded tip portion C of arc shaped protrusion 5 a may be engaged by a correspondingly formed annular receiving groove E of the engagement member 21. Accordingly, an effective sealing engagement between the sealing member 3 and the enclosing member 21 of the beverage preparation machine is obtained.

The fact that portion P of the sealing surface 21 a of the engagement member cooperates with the capsule and is received in the annular space, allows having a centering effect of the capsule relatively to the engagement member 21.

In FIG. 6a (section side view D-D) corresponding to a view presenting the gaps 5 b of the arc shaped protrusions, portion P of the sealing surface 21 a only interacts with the vertical portion of step 4 a. In this portion of the gap 5 b, the tightness is ensured by the contact surfaces S1 and S2 only.

The flat annular bottom surface 2 d of annular space 6 which interconnects the neighboring step 4 a of the dedicated surface 4 and arc shaped protrusions 5 a extends to a radial distance respectively thickness asD as described above. The distance asD is preferably chosen such as to be equal to or slightly smaller than an annular radial thickness L of the sealing surface 21 a of the engagement member 21. In a preferred embodiment, thickness L is chosen to be between 0.5 to 2.0 mm, more preferably between 0.8 to 1.2 mm.

The annular space 6 preferably widens from the bottom surface 2 d towards the tip portions C of the neighboring arc shaped protrusions 5 a. Thereby, the respective upper ends of the base portions B of neighboring arc shaped protrusions 5 a are preferably distanced by a radial distance asD1 that is larger than the distance asD at the bottom surface 6 a. The distance asD1 is preferably chosen to be 0.2 to 0.3 mm larger than the radial thickness L of the sealing surface 21 a of the engagement member 21.

As illustrated in FIGS. 6a and 6b respectively, the sealing engagement of the sealing surface of the engagement member 21 may be limited to one of the sealing surface portions S1 or S3 respectively with step 4 a or the arc shaped protrusions 5 a. As the engagement member 21 is moved towards the flange-like rim 2 by pressure effect during closing and/or extraction, the sealing surface portions S1, S3 may deform in an elastic way and or plastic way the steps 4 a and/or the arc shaped protrusions 5 a and increase the contact surface area between these elements.

As a result, a sealing pressure is exerted about the whole circumference of the sealing surface 21 a onto the sealing member 3 thereby ensuring a sealing continuity.

Reference is now made to FIGS. 7 and 8 presenting second and third embodiment of the sealing member according to the present invention.

In these figures, the dedicated surface 4 is an inclined surface 4 b in which the inclined surface 4 b is inclined vis-à-vis the external surface 10 b of the base body 1.

In these proposed embodiments, the fluid tightness between the engagement member and the capsule 10 during extraction of the capsule will be provided by engagement of the sealing surface 21 a (not represented) between the inclined surface 4 b and the arc shaped protrusions 5 a.

The proposed embodiments show a capsule engagement member 21 with a given geometry however other geometries of the capsule engagement member may be envisaged.

In the same way, the dedicated surface is here described to be a step or an inclined surface but other configurations are available as for example a double step or any other suitable specific surface. 

1. A capsule designed for preparing a beverage upon injection of liquid into the capsule by a beverage preparation machine, the capsule having a longitudinal axis and comprising a cup-shaped base body for holding beverage preparation ingredients, a flange-like rim and sealing member, wherein the base body, the flange-like rim and the sealing member is made integrally from metallic material, as a one piece element, wherein the sealing member comprises a dedicated surface located on the base body at the junction with the flange-like rim and a projection comprising at least one series of arc-shaped protrusions protruding circumferentially on the flange-like rim, the dedicated surface and the arc-shaped protrusions of the sealing member are concentrically arranged such as to form an annular space there-between for receiving at least one sealing surface of a capsule engagement member of the beverage preparation machine.
 2. The capsule of claim 1, wherein the arc-shaped protrusions of one series of protrusions are arranged equidistant to the dedicated surface such as to form a circumferentially constant annular space between the dedicated surface and the arc-shaped protrusions.
 3. The capsule of claim 1, wherein the annular space extends over a radial distance between 0.25 and 0.80 mm.
 4. The capsule of claim 1, wherein the annular space radial distance is equal or less than the radial length of the sealing surface of a capsule engagement member.
 5. The capsule of claim 1, wherein the dedicated surface extends over a radial distance comprised between 0.1 and 0.6 mm.
 6. The capsule of claim 1, wherein the dedicated surface is selected in the group of a step, an inclined surface, a double step or a combination thereof.
 7. The capsule of claim 6, wherein the step has a height comprised between 0.5 and 3 mm.
 8. The capsule of claim 6, wherein the inclined surface is inclined vis à vis the external surface of the base body.
 9. The capsule of claim 1, wherein a series of arc-shaped protrusions comprises at least two arc-shaped protrusions.
 10. The capsule of claim 1, wherein one series of arc shaped protrusions extends over a total angle comprised between 200 and 340°.
 11. The capsule of claim 1, wherein the angular overlap between the dedicated surface and the arc-shaped protrusions equals at least 60 to 95%.
 12. The capsule of claim 1, wherein the arc-shaped protrusions are arranged distant from the cup-shaped base body and from an outer periphery of the flange-like rim.
 13. The capsule of claim 1, wherein the annular space between the dedicated surface and the arc-shaped protrusions is void of any protrusion.
 14. The capsule of claim 1, wherein the arc-shaped protrusions are arranged at a radial distance of between 0.5 to 1.2 mm from the base body.
 15. The capsule of claim 1, wherein the capsule body, the flange-like rim and the sealing member is produced by deep drawing an initially flat metal sheet.
 16. The capsule of claim 1, wherein the capsule is made from aluminum.
 17. The capsule of claim 1, wherein the capsule further comprises a closing membrane connected to the base body and/or the flange-like rim of the capsule.
 18. The capsule according to claim 17, wherein the closing membrane is an aluminum foil sealed to the flange-like rim.
 19. A system comprising a capsule designed for preparing a beverage upon injection of liquid into the capsule by a beverage preparation machine, the capsule having a longitudinal axis and comprising a cup-shaped base body for holding beverage preparation ingredients, a flange-like rim and sealing member, wherein the base body, the flange-like rim and the sealing member is made integrally from metallic material, as a one piece element, wherein the sealing member comprises a dedicated surface located on the base body at the junction with the flange-like rim and a projection comprising at least one series of arc-shaped protrusions protruding circumferentially on the flange-like rim, the dedicated surface and the arc-shaped protrusions of the sealing member are concentrically arranged such as to form an annular space there-between for receiving at least one sealing surface of a capsule engagement member of the beverage preparation machine and a beverage preparation machine designed to provide heated and/or pressurized liquid into the capsule for preparing a beverage upon interaction of the liquid with ingredients held within the capsule.
 20. A cup-shaped base body of a capsule for holding beverage preparation ingredients and a flange-like rim with a sealing member comprising a dedicated surface and a projection comprising at least one series of arc-shaped protrusions protruding circumferentially on the flange-like rim, wherein the base-body, the flange-like rim and the sealing member are made integrally from metallic material such as aluminum, wherein the dedicated surface and the series of arc-shaped protrusions of the sealing member are concentrically arranged on a surface of the flange-like rim such as to form an annular space there-between for receiving a sealing surface of a capsule engagement member of the beverage preparation machine, wherein the arc-shaped protrusions of the series arc-shaped protrusions are continuous protrusions with circumferentially extending gaps formed there-between. 